Percardiac closure of large apical ventricular septal defects in infants: Novel modifications and mid-term results.

BACKGROUND/AIM: Both open heart surgery and percutaneous approaches retain several limitations in closing large apical muscular ventricular septal defects (AmVSD) in infants. We present probe-assisted percardiac device closure (PDC), an exclusively transoesophageal-echocardiography guided technique, as an alternative with midterm results. METHODS: Thirty-six infants with large AmVSDs (single or multiple-holed) underwent PDC in our department. Mean AmVSD for single and multiple-holed measured 7.2 ± 2.4 mm and 6.3 ± 3.4 mm, respectively. Subjects presented with a spectrum of cardiopulmonary sequelae and growth retardation, either alone or combined. Some were ventilator dependent and re-do cases. In addition, AmVSDs were categorized: cylindrical, tunnel and cave-like shaped as per color Doppler interrogation. Pursuant to cardiac access and deployment technique, subjects were apportioned: group A; inferior median sternotomy (perventricular), B; right mini-thoracotomy (peratrial) and C; complete median sternotomy (perventricular). Under exclusive echocardiography, the Z- or J probe-assisted delivery system was utilized to access AmVSDs and implant device(s) via aforementioned techniques. RESULTS: Forty-two muscular ventricular septal devices (8.4 ± 2.6 mm) were implanted in 36 subjects uneventfully. Seventeen "complex," and 10 cylindrical or straight tunnel-shapedAmVSDs (including 2 re-do patients) suited perventricular and peratrial techniques respectively. Comparatively, group B exhibited shorter procedural indices than A (p < .01). Five of 15 multiple-holed AmVSDs (four Swiss cheese) required two or three devices for a satisfactory occlusion. Nevertheless, post occlusion insignificant residual shunts( ≤ 2 mm) seldom achieved spontaneous closure, and at 36-month follow-up complete closure was 67%. Residual shunt persisted amongst multiple-holed. All patients improved during follow up. CONCLUSION: PDC is feasible, safe and effective alternative technique for AmVSD in infants.

Peratrial Balloon Pulmonary Valvotomy in Infants: Right Ventricular Wall None-Touch Technique.

Peratrial balloon pulmonary valvotomy, an alternative technique for severe pulmonary valve stenosis (PVS) in infants, performed exclusively under transesophageal echocardiographic guidance, is hereby described. The technique is performed using a hollow probe through a right minithoracotomy in the fourth intercostal space. The hollow probe introduces a guidewire through the PVS without touching the right ventricular wall, therefore avoiding eliciting ventricular arrhythmias, spasm of the right ventricular outflow tract, and subsequent hemodynamic instability. Unlike conventional approaches, the peratrial technique permits quicker orientation and dilatation and allows quick conversion to open heart surgery when needed.

Metallic-State SnS2 Nanosheets with Expanded Lattice Spacing for High-Performance Sodium-Ion Batteries.

Metallic-state 2D SnS2 nanosheets with expanded lattice spacing and a defect-rich structure were synthesized by the intercalation of Ni into the van der Waals gap of SnS2 . The expanded lattice spacing efficiently enhanced the electrochemical performance of the SnS2 for sodium-ion batteries owing to the change electron state density and energy band structure. In operando synchrotron XRD and theoretical calculations were used to gain insight into the influence of foreign metal-ion doping and its location. The optimized architecture obtained by in situ uniform growth of nanosheets on carbon fibers significantly enhanced the electrochemical performance. The inherent advantages of this architecture are shorter paths for ion insertion and extraction, larger contact area for more sodium diffusion pathways, and superior electrolyte penetration. Benefiting from the Ni intercalated SnS2 bilayer, the internal adjustment of the electronic state and the enlarged interlayer spacing significantly enhanced the electron transport kinetics, which can be explained by the metallic-state properties. The integrated electrode exhibited an initial high reversible capacity of 795 mAh g-1 at 0.1 A g-1 , with a stable capacity retention of 666 mAh g-1 after 100 cycles. Good rate capability was also exhibited with specific capacities of 691, 564, 437 mAh g-1 at current densities of 200, 500, and 1000 mA g-1 , respectively.